Hello there all you serious and knowledgeable Space Exploration and Space Flight fans .

Please would you take time to answer some questions I have? These are some points that stood out for me when I watched a video of an interview with Neil Armstrong, about working towards the first Moon landing(the simplest possible explanations would be appreciated ..... thank you):

1 Before anyone actually landed on the Moon, how did scientists know it had low gravity?

2 ditto 'No atmosphere on the Moon'? He(Armstrong), said "You're flying in a vacuum" .... how did they know that?

3 He said they had 20secs of fuel left when they landed. Why didn't they have more fuel on board? I know it's all extra weight, but seriously ..... 20secs?!!

4 Why have the Russians never attempted to put a man on the Moon? Finance wouldn't be a problem, surely? At least they would then be equal, not 'less' than their arch-rivals the Americans.

5 Have the Russians ever claimed that the Americans did not land on the Moon?

Before you say "why don't you all Google this?", I know I could but I probably wouldn't be able to understand half of it! I would like to be able to communicate with a real person who can answer any secondary questions I have.

Thank you.

Life is all too much ............................................. and not enough.

It is only when you form your question precisely and accurately that you receive the true answer.

I know? a little. I'm sure there is a formula in math that can use the size of the object to calculate the gravity. The fuel issue wasn't planned - they either over flew the landing site or couldn't find it as planned so they had to improvise. When you listen to the team on the radio they say "you've got a bunch of guys about to turn blue here" or something like that. Until I heard the full story later that comment didn't make much sense.
I've never heard the Russians question the truth of the landing. I think the issue with vacuum was assumed since there was never any observable weather on the moon's surface. That's all I can guess on - someone will come along directly and REALLY explain it I'm sure

We've cast the world, we've set the stage, for what could be, the darkest age...“This is like playing poker with a guy who cheated you twice before. You know who does that, a moron.

You can work out gravity from mass and distance, and mass from distance and orbit. Even the ancient greeks work distance out to within 8,000 miles, which is something you can look up if you want the exact method. The Russians? no they never claimed the Americans never landed on the moon, I can't think of any reason why the Russians would want to make themselves look incompetent by making up something like that.

"Equipped with his five senses, man explores the universe around him and calls the adventure Science". ~ Edwin Powell Hubble

The pull of gravity is the mass of one object multiplied by the mass of another object, then divided by the square of half the distance between the two objects. If one object (the moon) has substantially less mass than another object (Earth), it will pull much more weakly on a a nearby object (an astronaut). I forget how they derived the mass of the moon, though...

The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" but "That's funny..." --Isaac Asimov

Conspiracy theorists are created by the government to distract us from what they're really doing!!!! Or not.

1 Before anyone actually landed on the Moon, how did scientists know it had low gravity?

The surface gravity an object is a direct result of it's mass and radius.

The radius of the Moon can be directly measured.

Mass can be determined by using Kepler's 3rd Law, which relates the mass of a body to the distance at which if orbits an other (in this case the Earth) and the period it takes to complete an orbit. Since the distance from the Earth to the Moon can be measured, as can the time the Moon takes to complete one orbit it's mass can be determined.

Since the Moon's mass and radius are known it's surface gravity can be calculated.

ouija ouija, on 26 March 2014 - 05:37 PM, said:

2 ditto 'No atmosphere on the Moon'? He(Armstrong), said "You're flying in a vacuum" .... how did they know that?

That the Moon has no atmosphere has been known since Victorian times. It is simple to prove. When the Moon occults (passes in front of) a star if there is an atmosphere the star will visibly dim before the Moon cuts off all it's light. If there is no atmosphere the star will simply disappear as the Moon passes in front of it. The second of these scenarios is what is actually observed, therefore the Moon was known to have no atmosphere.

ouija ouija, on 26 March 2014 - 05:37 PM, said:

3 He said they had 20secs of fuel left when they landed. Why didn't they have more fuel on board? I know it's all extra weight, but seriously ..... 20secs?!!

As Apollo 11 came in to land Armstrong noticed that they were heading towards a boulder field. He took manual control and over-flew the original landing point. This used more fuel than was originally calculated.

ouija ouija, on 26 March 2014 - 05:37 PM, said:

4 Why have the Russians never attempted to put a man on the Moon? Finance wouldn't be a problem, surely? At least they would then be equal, not 'less' than their arch-rivals the Americans.

The Russians did attempt a manned Moon programme. They had huge problems with there equivalent of the Saturn V, known as the N1. In 4 launch attempts between February 1969 and November 1972 it exploded 4 times. The Soviet Union abandonded it's Moon programme in 1974.

ouija ouija, on 26 March 2014 - 05:37 PM, said:

5 Have the Russians ever claimed that the Americans did not land on the Moon?

Well some individuals have, but the Soviet government congratulated the USA on it's achievement.

Edited by Waspie_Dwarf, 27 March 2014 - 09:25 AM.

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

Armstrong was actually down to a 30 secondlanding fuel warning - that didn't mean it would run out in 30 seconds. The warning was so he knew IF he had to abandon the landing attempt, he needed to do it within 30 seconds or so, or he might not have enough fuel to re-ascend into orbit and safely dock with the orbiting CSM..

If he had aborted and re-ascended to the CSM without landing, he and his crew would have been able to safely return to Earth, but they would have missed their chance to be first.... and the crew of Apollo 12 would have been the next to try.. Needless to say that was quite an incentive for him! So he made the judgement to continue, got it down safely well within the safe time limit and his judgement was dead right.

Many reports of the landing neglect to explain what the 30 second warning actually meant, preferring the implied drama that they were about to crash!!! But the 30 seconds was a carefully calculated value for a safe decision point and it left a significant safety margin. So he would have known that in reality he had more time than that to truly make the final decision. Even though it would have given some mission control staff heart attacks! (Somewhere those margins are available - if you want I can chase them down..)

Also, note that not only did the Russians congratulate the USA (perhaps grudgingly - it certainly wasn't as well promoted in the Russian press!), they had to.. They had tracked the mission all the way to the moon and also listened in to the transmissions by intercepting them with directional antennas pointed at the moon (it is impossible to fake that). In addition, apart from any spying that the Russki's were doing, the entire Apollo mission was incredibly openly and comprehensively documented - anyone could verify all the technical details (and many did and still do). This unprecedented openness happened largely because of the terrible Apollo 1 tragedy which cost 3 lives and almost killed off the Moon program. NASA knew that it had to change its approach completely, and what better way than to open the mission to high level scrutiny by anyone and everyone.

IMNSHO, the Apollo project was without doubt the most ambitious technical achievement ever undertaken by mankind, and I doubt whether anything we do will ever overtake it in terms of the huge leap in our technical abilities that it demonstrated. I can still vividly remember the drama leading up to the landing and the way the entire world came together and held its breath... and then the euphoria when they made it and also returned safely... Those were wonderful times, even if it was all fairly shortlived. By the time we got to Apollo 17, it seemed that it had all become routine.. (not to me, though!)

Sadly we live in a different world now...

All my posts about Apollo are dedicated to the memory of MID - who knew, lived and was an integral part of, Apollo.

My garden is already magical and beyond beautiful - I do not need to invent fairies... - ChrLzs

"Sadly we live in a different world now..." so true, I was fascinated with it all but it got boring after a while as the TV didn't show much of what was going on in my part of the world, just printed 'news reports'.

I be Ra...The river of life, the ebb and flow of summer tides...
Make not an image of me, nor offer unto me the limitations of form...
For I be Soul....and I will not be limited...

IF he had to abandon the landing attempt, he needed to do it within 30 seconds or so, or he might not have enough fuel to re-ascend into orbit and safely dock with the orbiting CSM..

An addition to the addition.

The lunar module was actually 2 modules, the descent module and the ascent module. The ascent module used a different engine and had separate fuel tanks from the descent module. Even if the descent module HAD run out of fuel there would have been enough fuel to abort the landing and return to orbit.

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001

The lunar module was actually 2 modules, the descent module and the ascent module. The ascent module used a different engine and had separate fuel tanks from the descent module. Even if the descent module HAD run out of fuel there would have been enough fuel to abort the landing and return to orbit.

Yup, exactly.. It's an interesting topic and I've seen some discussion about the logistics of 'dropping' the descent module before they landed and then quickly lighting up the ascent stage's rocket to get back up... and I think the astronauts were a bit nervous about that possibility. If they left everything *way* too late and had to do all that close to the ground, it could have been nasty!

But as it turned out, the hardware performed so well that everything went wonderfully smoothly for every mission (but one.. and with a few tiny exceptions.. ) Given this was all developed and done in the 50's, 60's and early 70's, I think it is an absolutely brilliant example of just how clever we can be if motivated..

And all without Google, let alone a single personal computing device!!! Long live the slide rule, I say!

Edited by ChrLzs, 27 March 2014 - 12:11 PM.

All my posts about Apollo are dedicated to the memory of MID - who knew, lived and was an integral part of, Apollo.

My garden is already magical and beyond beautiful - I do not need to invent fairies... - ChrLzs

Given this was all developed and done in the 50's, 60's and early 70's, I think it is an absolutely brilliant example of just how clever we can be if motivated..

In February 1945 my father (who was 8 at the time) received what he referred to as, "a present from Werner Von Braun," a scar on his head from the impact of a V2 that hit the suburbs of London.

Just over 24 years later, as a three year old, I sat on my fathers lap and watched 2 men walk on the Moon, the result of a present to the entire human race from the same Werner Von Braun.

Today rockets have the capability to send us all to oblivion or to send us to other worlds. To end the human race or to make our species virtually immortal. I think (hope) we will choose the latter.

Edited by Waspie_Dwarf, 27 March 2014 - 01:03 PM.

"Space is big. Really big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the street to the chemist, but that's just peanuts to space." - The Hitch-Hikers Guide to the Galaxy - Douglas Adams 1952 - 2001